1. chemistry

2. 24.2
Carbohydrates
This cicada is shedding its old exoskeleton and forming a new one. An arthropod’s exoskeleton is made of a polymer called chitin, which belongs to a class of organic molecules known as carbohydrates. You will learn about the structures and functions of carbohydrates.

3. Monosaccharides Where is glucose found abundantly in nature? 24.2

4. 24.2
Monosaccharides
Carbohydrates are monomers and polymers of aldehydes and ketones that have numerous hydroxyl groups attached; they are made up of carbon, hydrogen, and oxygen.

5. Glucose is abundant in plants and animals.
24.2
Monosaccharides
The simplest carbohydrate molecules are called simple sugars, or monosaccharides. Glucose and fructose are examples of monosaccharides.
Glucose is abundant in plants and animals.

6. Carbohydrates are the most abundant sources of energy in food.
24.2
Monosaccharides
Carbohydrates are the most abundant sources of energy in food.
Carbohydrates are the most abundant sources of energy in food. Fruits contain simple carbohydrates called sugars. Bread and pasta are good sources of complex carbohydrates called starches.

7. 24.2
Monosaccharides

8. 24.2
Monosaccharides

9. Disaccharides and Polysaccharides
24.2
Disaccharides and Polysaccharides
Disaccharides and Polysaccharides
How can the cyclic forms of two simple sugars be linked?

10. Disaccharides and Polysaccharides
24.2
Disaccharides and Polysaccharides
The cyclic forms of two simple sugars can be linked by means of a condensation reaction.
A sugar such as sucrose that forms from two monosaccharides in this way is known as a disaccharide.

11. Disaccharides and Polysaccharides
24.2
Disaccharides and Polysaccharides

12. Disaccharides and Polysaccharides
24.2
Disaccharides and Polysaccharides
The polymers produced by the linkage of many monosaccharide monomers are called polysaccharides.
Starches, the major storage form of glucose in plants, are polysaccharide polymers that consist of glucose monomers.

13. Disaccharides and Polysaccharides
24.2
Disaccharides and Polysaccharides
Starch and cellulose are similar polymers made up of hundreds of glucose monomers. They differ in the orientation of the bond between the glucose units. Because of this difference, starch is readily digestible, but cellulose is indigestible by most organisms. Using Models What other types of models could you use to show the structural differences between starch and cellulose?

14. 24.2 Section Quiz.
24.2.

15. 24.2 Section Quiz.
1. Many carbohydrates have the general formula
Cn(H2O)2n.
(COH)n.
Cn(OH)2n.
Cn(H2O)n.

16. 24.2 Section Quiz.
2. Sucrose is an example of a
starch.
polysaccharide.
monosaccharide.
disaccharide.

17. 24.2 Section Quiz.
3. Choose the correct words for the spaces. Starches are polymers formed by linking together ________ molecules in a condensation reaction that eliminates ________ molecules.
glucose, water
fructose, hydrogen
sucrose, carbon dioxide
glucose and fructose, water

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